1 files changed, 82 insertions, 0 deletions
diff --git a/arch/x86/kernel/paravirt_patch_32.c b/arch/x86/kernel/paravirt_patch_32.c
new file mode 100644
index 000000000..758e69d72
--- /dev/null
+++ b/arch/x86/kernel/paravirt_patch_32.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <asm/paravirt.h>
+
+DEF_NATIVE(pv_irq_ops, irq_disable, "cli");
+DEF_NATIVE(pv_irq_ops, irq_enable, "sti");
+DEF_NATIVE(pv_irq_ops, restore_fl, "push %eax; popf");
+DEF_NATIVE(pv_irq_ops, save_fl, "pushf; pop %eax");
+DEF_NATIVE(pv_cpu_ops, iret, "iret");
+DEF_NATIVE(pv_mmu_ops, read_cr2, "mov %cr2, %eax");
+DEF_NATIVE(pv_mmu_ops, write_cr3, "mov %eax, %cr3");
+DEF_NATIVE(pv_mmu_ops, read_cr3, "mov %cr3, %eax");
+
+#if defined(CONFIG_PARAVIRT_SPINLOCKS)
+DEF_NATIVE(pv_lock_ops, queued_spin_unlock, "movb $0, (%eax)");
+DEF_NATIVE(pv_lock_ops, vcpu_is_preempted, "xor %eax, %eax");
+#endif
+
+unsigned paravirt_patch_ident_32(void *insnbuf, unsigned len)
+{
+	/* arg in %eax, return in %eax */
+	return 0;
+}
+
+unsigned paravirt_patch_ident_64(void *insnbuf, unsigned len)
+{
+	/* arg in %edx:%eax, return in %edx:%eax */
+	return 0;
+}
+
+extern bool pv_is_native_spin_unlock(void);
+extern bool pv_is_native_vcpu_is_preempted(void);
+
+unsigned native_patch(u8 type, u16 clobbers, void *ibuf,
+		      unsigned long addr, unsigned len)
+{
+	const unsigned char *start, *end;
+	unsigned ret;
+
+#define PATCH_SITE(ops, x)					\
+		case PARAVIRT_PATCH(ops.x):			\
+			start = start_##ops##_##x;		\
+			end = end_##ops##_##x;			\
+			goto patch_site
+	switch (type) {
+		PATCH_SITE(pv_irq_ops, irq_disable);
+		PATCH_SITE(pv_irq_ops, irq_enable);
+		PATCH_SITE(pv_irq_ops, restore_fl);
+		PATCH_SITE(pv_irq_ops, save_fl);
+		PATCH_SITE(pv_cpu_ops, iret);
+		PATCH_SITE(pv_mmu_ops, read_cr2);
+		PATCH_SITE(pv_mmu_ops, read_cr3);
+		PATCH_SITE(pv_mmu_ops, write_cr3);
+#if defined(CONFIG_PARAVIRT_SPINLOCKS)
+		case PARAVIRT_PATCH(pv_lock_ops.queued_spin_unlock):
+			if (pv_is_native_spin_unlock()) {
+				start = start_pv_lock_ops_queued_spin_unlock;
+				end   = end_pv_lock_ops_queued_spin_unlock;
+				goto patch_site;
+			}
+			goto patch_default;
+
+		case PARAVIRT_PATCH(pv_lock_ops.vcpu_is_preempted):
+			if (pv_is_native_vcpu_is_preempted()) {
+				start = start_pv_lock_ops_vcpu_is_preempted;
+				end   = end_pv_lock_ops_vcpu_is_preempted;
+				goto patch_site;
+			}
+			goto patch_default;
+#endif
+
+	default:
+patch_default: __maybe_unused
+		ret = paravirt_patch_default(type, clobbers, ibuf, addr, len);
+		break;
+
+patch_site:
+		ret = paravirt_patch_insns(ibuf, len, start, end);
+		break;
+	}
+#undef PATCH_SITE
+	return ret;
+}